Apparatus and process for the manufacture of mineral wool



E. R. POWELL Oct. 12, 1948.

APPARATUS AND PROCESS FOR THE MANUFACTURE OF MINERAL WOOL Filed Sept.16, 1943 m m i mm L. DY m i Patented Qct. 1 2

UNITED STATES PATIENT orrics APPARATUS AND PROCESS FOR THE MANU- FACTUREOF IHINERAL WOOL Edward R. Powell, North Plainfield, N. 1., assignor toJohns-Manville Corporation, New York, N. Y., a corporation of New YorkApplication September 16, 1943, Serial No. 502,572

' 14 Claims.

. 1 My present invention ture of mineral wool, and more particularly toan improved apparatus and method for converting molten raw material'intofibers and for forming a mat or felt therefrom. The term mineral wool isemployed herein in a generic sense to include wool or fibers formed fromrock, slag, glass, mixtures thereof, and like raw materials.

Heretofore mineral wool has been made in a number of ways including theconventional method of disintegrating'molten material into amultiplicity of fibers by the action of a high pressure steam jet, andgathering the fibers on the floor of a blow chamber adjacent theflberizing means. More recently it has been proposed to fiberize themolten material by the use ofa spinner or rotor, rotated at high speed,upon which the .material impinges and by which it is broken up into 1drops or masses which are thrown from the spinner by centrifugal forceto be drawn into. fiber or thread form. The principal object of theinvention is the provision of an-apparatus and method employed inconjunction with the spinning operation to provide both improved fibersand improved fibrous felts or mats.

Another object of the invention is the provision of a method andapparatus in which longer, finer fibers are produced from the moltenmaterial.

A further object of the invention is the provision of a method andapparatus for forming an improved felt or mat of spun mineral woolfibers. A still further object is the provision of such felt or matincluding a substantially. uniformly disseminated binder material. Moreparticularly the invention resides in means for initially gathering thespun fibers on a rapidly moving body whereby the fibers are furtherelongated and drawn out, and the resuspension of the fibers in the formof a thin layer in air or other gaseous medium. While the fibers are inthis state the binder is applied in the form of a spray or the like, andthe fibers or fibrous layer thereaftercollected in the form of arelatively thick blanket or felt.

My invention will be more fully understood and further objects andadvantages thereof willbecome apparent'when reference is made to themore detailed description thereof, which is to follow, and to theaccompanying drawings, in

- which:

relates to the manufac-' 2 away for clearness of illustration, taken ona line 22 of Fi 1.

Referring now to the drawings, there is shown an apparatus comprising amelting furnace I0.

The furnace illustrated is of the cupola type, but it will be understoodthat any other suitable type of melting furnace, such as a tank furnace,may be employed, if desired. The furnace includes a discharge trough l2,by, which a stream of molten slag, rock, glass or other fiber formingmaterial is drawn from the furnace and is discharged in position'to becontacted by one or more rotors I4, rotating at high speed. The rotorsmay be of the type, illustrated in my copending application, Serial No.485,009, filed April 29, 1943 which issued as United States Patent No.2,428,810 on October 14, 1947. The molten material striking the rotor orrotors is broken up into fine drops which are thrown out from the rotorsat a high velocity and converted into fiber form.

In accordance with the instant invention, a

drum I6 is mounted for rotation in a direction indicated by the arrow,relatively closely adjacent the fiberizing rotors. Drum l6 includes aforaminous surface made, for example, of a relatively coarse mesh screenor the like. Preferably, however, a perforated metal sheet or sheets areemployed. Metal sheets having perhood and other means to be described.For this purpose, the drum may, as shown, have an end plate l8 carryingthe foraminous peripheral wall 20. End plate i8 is secured as by plate22 to a shaft 24, mounted for rotation within bearings 28 of supports28. Shaft 24 is adapted to be driven at high speed in any suitablemanner, as for example by a motor 30 operatively connected to the shaftthrough chain 32 and sprocket-34.

Within drum Hi there is provided a suction hood 36, connected by meansof a suction main 38 with an air exhausting device (not shown). Thesuction hood is positioned to draw air through a.

considerable area of the foraminous surface of the drum adjacent thefiberizing means It. The hood 36 is sealed against the surface of thecylinder, and against end member l8, as by flexible wipers 40. The otherend of the hood is closed a by end member l9. Extending inside thecylinside of the suction box.

der and at the other side of the cylinder from the fiberizing area is apipe 42, adapted to be connected to a source of air or other gaseousfluid under pressure and supported in a fixed position in any suitablemanner. The inner end of the pipe is closed 011 with a cap, plug or thelike 43. The length of the pipe extending within the drum is providedwith a plurality of air jet nozzles 44 of any suitable type. As shown,the nozzles may comprise individual members connected into pipe 42 byball and socket joints to permit the outer ends of the nozzles to bemoved. A bar 45 is supported for reciprocation in a suitable bar support48 and is pivotally connected to the several nozzles. The bar is adaptedto be reciprocated by means of a cam 48 driven from any suitable sourceof power (not shown), the cam acting on a follower 50 carried by thebar. A spring 52 may be employed to maintain the follower in contactwith the cam or any other conventional cam and follower construction maybe used to achieve this purpose. It will be understood that theinvention is not limited to the particular construction shown, and, thatother suitable means may be employed to substantially continuously varythe direction of the air jets issuing from the nozzles.

In certain instances it is desirable to provide a press roll, asindicated at 56, supported for rotation above cylinder I8, whereby thefibers collected on cylinder I 6 are compacted and densi fied to someextent as they pass between the two rolls. Roll 56 may preferably bedriven at subsiantially the same peripheral velocity as drum One or morebinder applying devices 58 are preferably supported adjacent drum I6 inposition to spray a suitable binder on the fibers after leaving drum I6.Preferably one is located above and one below the discharged stream offibrous material. Each device 58 may comprise an elongated spray head 59connected to a binder supply source. The spray head may be of aconventional type adapted to spray any one of the binders conventionallyemployed, such as asphalts, drying oils, resins, waxes, etc., inrelatively finely. divided, droplet form.

An inclined conveyor Gil, preferably somewhat wider than drum I6, islocated adjacent the drum in position to receive the material dischargedfrom the drum. The conveyor is driven from any suitable power source(not shown), and at a speed determined by the rate of production of thefibers and the character'and thickness of the felt or mat to be formed.

In the operation of the apparatus in accordance with the invention,suction box 36 is connected through duct 38 with any desired exhaustingmeans to create a flow of air through the foraminous surface of the drumas it passes the open Drum I6 is rotated at a relativelyhigh speed, suchas to have a surface speed, say of from 600 to 2,000 feet per minute.Air or other gaseous fluid under pressure is supplied to pipe 42 andescapes as a plurality of jets through the nozzles 44, the jets blowingthrough the foraminous surface of the drum at the side adjacent conveyor60.

As the molten material delivered by trough I2 strikes the high speedrotor or rotors I4, it is divided into minute droplets or pellets andthrown from the rotor by centrifugal force to be drawn out intorelatively fine threads. Due to the movement of air through theforaminous surface of the drum created by suction box 8 the 4 outer endsof the fibers are substantially immediately attracted to the surface ofthe drum and. due to the high speed of rotation of the drum. the fibersare further drawn out and extended, with the result that a longer, finerfiber is produced than with the use of the rotors alone. Also a highfiber yield is obtained.

The fibers are collected on the surface of the drum in the form of athin, low density, open lap or layer. It has been found in practice thatthe layer thus formed is, at least for the most part, relatively narrowand of varying position on the drum. The layer is carried by rotation ofthe drum in front of the nozzles 44. Through a combination of thecentrifugal forces created by rotation of the drum and the action of thejets issuing from the nozzles, the layer or lap is stripped from thedrum and, due to its low density, is suspended in the air stream createdby the jets and driventoward the conveyor 80. The surface of the drum isleft relatively clean. Due to the change of direction of the jets by thereciprocation of the nozzles, the lap or layer is directed back andforth across the conveyor '8 to reassemble it thereon and to build up asubstantially uniform body or felt, the thickness of which may becontrolled by regulation of the speed of conveyor 6B. Suitably the layeris built up to provide a thickness of the final product of from /2" to4". During the interval that layer of fibers is suspended in the airstream, a binder of any suitable type, as previously referred to, may besprayed on to the fibers through sprayheads in. Due to the thin and opencharacteristics of the layer at this stage, the binder is welldistributed throughout it. In the felt or blanket built up on conveyor60 the binder is found to be substantially uniformly disseminatedwhereby, in the final product, a coherent batt or blanket is obtained.

-In addition to the advantages obtained by the present apparatus andprocess in superior fiberization, felting, and binder distribution, theinvention has the advantage that the binder is applied when the fibersare comparatively cool. That is, as distinguished from conventionalprocesses, the binder does not contact the incandescent molten materialor portions of the apparatus heated above the flash point of the binder.Consequently, ignition loss of binder is greatly reduced and also a moreemcient binding of the fibers is achieved.

The blanket or felt formed on the conveyor 89 may be compressed to,theextent desired and treated in any suitable way to set the binder inaccordance with known practice, such treatment depending of course onthe type 01 binder employed. The blanket may then be trimmed and dividedinto batts or the like to adapt it to commercial uses.

Having thus described my invention in rather full detail, it will beunderstood that these details need not be strictly adhered to, but thatvarious changes and modifications. will suggest themselves to oneskilled in the art, all falling within the scope of the invention asdefined by the subjoined claims.

What I claim is:

1. In a mineral wool apparatus having means for disintegratlnga streamof molten material into fibers, a drum including a fiber receiving areaadjacent said means, a foraminous surface on said drum, means forrotating said drum, and means for blowing a current of a gaseous mediumt rough said foraminous surface at a point remote from said fiberreceiving area whereby 'said fibers are forced from said drum.

2. In a mineral wool apparatus having means 'for disintegrating a streamof molten material into fibers, a drum including a fiber receiving areaadjacent said means, a foraminous surface on said drum, a suction devicebehind said fiber receiving area, and means for blowing a current of aaseous medium through said foraminous surface at a point remote fromsaid fiber receiving area.

3. In a mineral wool apparatus having means for disintegrating a streamof molten material into fibers, a drum including a fiber receiving areaadjacent said means, a foraminous surface on said drum, suction meansbehind aid fiber receivin area and acting therethrough, means forrotating said drum at high velocity, means for blowing a current of agaseous medium through said foraminous surface at a location remote fromsaid fiber receiving area whereby said fibers are removed from saiddrum-and means for spraying a binder into said fibers upon removal fromsaid drum.

4. In a mineral wool apparatus including means for disintegrating astream of molten material into fibers, a drum including a fiberreceiving area adjacent said means, a foraminous surface on said drum,suction means behind said fiber receiving area and acting therethrough,means for rotating said drum at high velocity, means for blowing acurrent of a gaseous medium through said foraminous surface at alocation remote from said fi-ber receiving area whereby said fibers areremoved from said drum in the form of a thin layer suspended in air,means for spraying a binder into said suspension of fibers, and aconveyor positioned to receive said fibers from said suspension in theform of an'interfelted layer.

5. In a mineral wool apparatus having a rotor for disintegrating astream of molten material into fibers, a drum having a foraminoussurface mounted for rotation adjacent said rotor and in position toreceive fibers thereon, suction means operating through said foraminoussurf-ace adjacent said rotor, a pipe extending substantially the lengthof said drum and at a location removed from the fiber receiving portionof the drum behind said foraminou-s surface, said pipe including aplurality of nozzles positioned to discharge a gaseous medium throughsaid surface.

6. In a mineral wool apparatus having a rotor for converting moltenmaterial into fibers, a drum having a foraminous surface, said drumbeing located adjacent the rotor, suction means operating through theforaminous surface of the drum adjacent the rotor, means for rotatingsaid drum at high speed, and means within said drum and at a locationremote from said rotor for causing a flow of a gaseous medium in a.varying direction outwardly through said foraminous surface.

7. In a mineral wool apparatus having a rotor for converting moltenmaterial into fibers, a drum having a f-oraminous surface, said drumlying adjacent the rotor, suction means operating through saidforaminous surface adjacent said rotor, means for rotating said drum athigh speed, an air pipe within said drum at a location remote from saidrotor and including a plurality of nozzles positioned to direct air jetsthrough said foraminous surface, and means for longitudinallyreciprocating said nozzles.

8. In a mineral wool apparatusincluding rotor fiberizing means forconverting a molten material into fibers, said means being supported forrotation in a plane to expose a peripheral edge portion to the moltenmaterial, an air-pervious fiber receiving member having a fiberreceiving area located closely adjacent said rotor means .and projectingbeyond the periphery thereof, suction means acting through said area,means for moving said member at high speed relative to the rate of fiberformation to collect the fibers in the form of a thin, narrow layerthereon, means for forcing said layer from said member, and means forassembling the fibers of said layer into a thicker, wider, fibrous body.

9. In a mineral wool apparatus including rotor fiberizing means forconverting a molten material into fibers, said means being supported forrotation in a plane to expose a peripheral edge surface to the moltenmaterial, a rotatable drum having an air-pervious peripheral surfacewith a fiber receiving area thereof located closely adjacent the rotormeans and projecting beyond the periphery thereof, suction means actingthrough said area, means for rotating said drum at high speed relativeto the rate of fiber formation to collect the fibers in the form of athin, narrow layer thereon, means for forcing the layer from the drum,and means for assembling the fibers of said layer into a thicker, widerfibrous body.

10. In a mineral wool apparatus including rotor fiberizing means forconverting a molten material into fibers, said means being supported forrotation in a plane to expose a peripheral edge surface to the moltenmaterial, a rotatable drum having an air-pervious peripheral surfacewith a fiberreceiving area thereof located closely adjacent the rotormeans and projecting beyond the periphery thereof, suction means actingthrough said area, means for rotating said drum at high speed relativeto the rate of fiber formation to collect the fibers in the form of athin, narrow layer thereon, means for forcing the layer from the drum,means to deposit a binder on the layer, and means for assembling athicker, wider, fibrous body from the layer.

11. In a mineral wool apparatus including rotor fiberizing means forconverting a molten material into fibers, said means being supported forrotation in a plane to expose a peripheral edge to the molten material,a drum having an air-pervious fiber receiving surface area locatedclosely adjacent the rotor means and projecting beyond said means, meansfor rotating said drum at a peripheral velocity above 600 feet perminute, suction means acting through said area, and means for forcingthe fibers from the drum and assemblin them in the form of a body.

12. In a method including converting a molten material into fibers bydischarging the material onto a peripheral edge surface of a rotorfiberizing means, the steps comprising, directing the ends of the fiberssubstantially as they are formed onto a surface moving past said rotormeans at high speed and in close proximity thereto to collect the fiberson such surface in the form of a thin, narrow layer, removing the layerfrom said surface and assembling the fibers thereof into a relativelythick, wide body.

13. In a method including converting a molten material into fibers bydischarging the material onto a peripheral edge surface of a rotorfiberizing means, the steps comprising, directing the ends of the fiberssubstantially as they are formed onto a surface moving past said rotormeans at a speed of'above 600 feet per minute and in close proximitythereto to collect the fibers on such surface in the form of a thin,narrow layer, re-

7 moving the layer from said surface and assembling the fibers thereofinto a relatively thick, wide body.

14. In a method including converting a molten material into fibers bydischarging the material onto a peripheral edge surface of a rotorflberizing means, the steps comprising, directing the ends of the fiberssubstantially as they are formed onto a surface moving past said rotormeans at high speed and in close proximity thereto to collect the fiberson such surface in the form of a thin, narrow layer, removing the layerfrom said surface, depositing a binder on the layer and assembling thelayer in a relatively thick, wide body.

EDWARD R. POWELL.

REFERENCES CITED Number file of this patent:

UNITED STATES PATENTS Name Date Elbers Aug. 1, 1876 Grayson May 15, 1934Thomas Oct. 8, 1935 Vieweg Mar. 8, 1938 Carson Aug. 16, 1938 Pearce Jan.30, 1940 Thomas Mar. 12, 1940 Siegfried May 28, 1940 Simpson Feb. 4,1941 Davis Feb. 24, 1942 Collins June 30, 1942 McClure May 4, 1943 CossAug. 3, 1943 Von Pazsiczk Nov. 2, 1943 Callander Aug. 14, 1945 FOREIGNPATENTS Country Date Netherlands Apr. 17, 1934

